Tinderbox is Hobart's home shore dive and, as the Parks and Wildlife Service puts it, Tasmania's most accessible marine reserve. It was one of the state's first four marine reserves, declared in September 1991 alongside Ninepin Point, Governor Island and Maria Island, and was later expanded. It is a fully protected no-take area: fishing and other extractive activities are prohibited, and the difference shows.

The older Marine Life Network guide notes that before protection, stocks of fish, crayfish and abalone were exceedingly low. The reserve's reefs are narrow bands of rock running along the shore. To the east of the boat ramp they drop to 6-10 m, while to the south-west they reach about 5 m before giving way to sand.

The Parks leaflet lists habitats of kelp forest, sponge gardens, seagrass beds and soft sediments, with 77 species of macroalgae and 60 fish species recorded. Highlights include big-belly seahorses, rock lobsters, bastard trumpeter, senator wrasse and octocorals, and weedy seadragons are regularly seen. On the sand and silt beyond the reef divers find brittle stars, cardinalfish, octopus, craylets and lace bryozoans.

The shallow gulches east of the ramp are ideal for snorkelling, and Tinderbox has long hosted a marked snorkel trail for learners and families. Most Hobart dive shops use Tinderbox for open-water training, and it is a very popular night dive. Visibility is modest by ocean standards and drops sharply after rain, but the sheltered position means it can be dived in almost any westerly weather.

Parks asks divers to avoid damaging fragile life, not to hold onto the reef, and to dive in small groups. Close by, 200 m from the ramp and marked by moorings, lies the Tinderbox artificial reef.

From Hobart drive south on the Southern Outlet to Kingston, continue through Blackmans Bay and follow Tinderbox Road to its end, then turn into Fergusson Avenue (about 25 km, 30 minutes). Parking is restricted to designated areas near the small Tinderbox Bay boat ramp; park only in these. Entry is from the shore close to the car park – a short walk – and the best snorkelling and shallow reef are in the gulches east of the ramp.

Stay at least 30 m from the ramp and boating channel. The ramp is small and only usable around low tide; larger boats launch at Dru Point, Margate.

The Kingborough coast south of Hobart faces east across the lower Derwent and the northern D'Entrecasteaux Channel, so it is sheltered from the prevailing westerlies – the main reason Hobart divers use it year-round. Easterly and south-easterly winds put chop and small swell onto the shore and churn up the sandy bottom; strong southerly swell entering Storm Bay can also wrap in. Heavy rain is the biggest factor for visibility: the Derwent and local creeks carry tannin-stained, silty runoff that can drop visibility to 1-3 m for days.

Tidal flow is weak. Best after dry spells with westerlies, and in the calm mornings of late summer and autumn; night dives are popular year-round.

Enter east of the boat ramp, swim out through the shallow gulches and follow the reef east as it drops to 6-10 m, exploring the kelp and sponge garden at the reef edge. Turn at half air and return along a shallower contour, surfacing well away from the ramp.

Go Dive Tasmania – Tinderbox listed as a shore site (3-12 m) for courses and guided dives; The Dive Shop Hobart and Tasmanian Divers (Kingston) – training and shore dives; Underwater Adventures Tasmania – northern boat dives; Tasmanian Scuba Diving Club – regular club dives.